Efficacy of Glutathione for Patients With Cystic Fibrosis: A Meta-analysis of Randomized-Controlled Studies

Introduction The impact of glutathione on pulmonary function remains elusive for patients with cystic fibrosis. The aim of this systematic review and meta-analysis is to explore the influence of glutathione versus placebo on pulmonary function of cystic fibrosis. Methods We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through May 2019, and randomized-controlled trials (RCTs) regarding the effect of glutathione on pulmonary function of cystic fibrosis are included in this meta-analysis. Results Four RCTs are included. Compared with control group in patients with cystic fibrosis, glutathione treatment shows positive impact on forced expiratory volume 1 second (FEV1) (mean difference [MD] = 0.19; 95% confidence interval (CI), 0.10-0.28; P < .0001) and body mass index (MD = 0.27; 95% CI, 0.02-0.51; P = .03), but has no obvious influence on 6-minute walk test (standard MD = 0.28; 95% CI, -0.08 to 0.64; P = .13), number of exacerbations (MD = -0.10; 95% CI, -0.34 to 0.15; P = .43), abdominal pain or distal intestinal obstruction (risk ratios [RR] = 0.78; 95% CI, 0.32-1.90; P = .58), or hemoptysis (RR = 1.87; 95% CI, 0.43-8.26; P = .41). Conclusions Glutathione treatment provides some benefits to improve pulmonary function of patients with cystic fibrosis, as evidenced by the increase in FEV1.